Editing XML with powershell

Question

OK, I'm feeling like a really big idiot here. I've been working with Powershell for a little while more for administrative purposes at work. That said, scripting is not my strong suit.

Right now, I'm trying to write a PS script to add a section to an XML on a bunch of machines to add settings to workaround an issue we've been having with a certain application

The XML file looks as follows

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
      <add Name="testdata"/>
  </configSections>
  <connectionStrings>
      <add Name="testdata"/>
  </connectionStrings>
  <ProvidersConfiguration>
    <Providers>
      <add Name="testdata"/>
    </Providers>
  </ProvidersConfiguration>
  <FacadeSettings>
    <Providers>
      <add Name="testdata"/>
    </Providers>
  </FacadeSettings>
</configuration>

now, I've been googling and searching for hours and there's something i'm just not getting. because i can load the file in my script, navigate all the settings, even modify existing values, but that's not what I need to do.

I need to add a section like this

<NewSettings>
    <add Name="setting"/>
  </NewSettings>

so that my config file looks like this

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
      <add Name="testdata"/>
  </configSections>
  <connectionStrings>
      <add Name="testdata"/>
  </connectionStrings>
  <ProvidersConfiguration>
    <Providers>
      <add Name="testdata"/>
    </Providers>
  </ProvidersConfiguration>
  <FacadeSettings>
    <Providers>
      <add Name="testdata"/>
    </Providers>
  </FacadeSettings>
   <NewSettings>
      <add Name="setting"/>
   </NewSettings>
</configuration>

it's the NewSettings section I can't figure out and I'm sure that when I wrap my head around it, I'll go "OH...", but right now I'm banging my head on the wall and could use some help

Answer 1

Try this:

# Create xml doc - assumes your xml is file E:\Scratch\test.xml
# If it's already in a variable, use $xml = [xml]$myVariable

$xml = [xml](Get-Content E:\Scratch\test.xml)

# Create new element for <NewSettings>
$newSettings = $xml.CreateElement("NewSettings")

# Create new element for <add>
$add = $xml.CreateElement("add")

# Create attribute "Name", and set its value
$settingsAttribute = $xml.CreateAttribute("Name")
$settingsAttribute.Value = "setting"

# Add attribute to <add>
$add.Attributes.Append($settingsAttribute)

# Add <add> to <NewSettings>
$newSettings.AppendChild($add)

# Add <NewSettings> to <configuration>
$xml.configuration.AppendChild($newSettings)

# Save to file
$xml.Save("E:\Scratch\new.xml")